Problem: What is the least common multiple of 25 and 45? Another way to say this is: $\lcm(25, 45) = {?}$
Explanation: The least common multiple is the smallest number that is a multiple of 25 and 45. We know that 25 x 45 (or 1125) is a common multiple, but is it the least common multiple? Write out the multiples of 45 until we find a number divisible by 25. 45, 90, 135, 180, 225, So, 225 is the least common multiple of 25 and 45.